Phase 3.5: Pause/Resume, SwiftData-Persistenz, Kamera-Capture, Fotos zu bestehender Tour

LocationTracker:
- isPaused, pausedAt, accumulatedPausedSeconds
- pause()/resume()/restore() Methoden
- effectiveElapsedSeconds rechnet Pausen raus
- restore() für nach App-Crash: Offline-Lücke wird als Pause gezählt

ActiveWalk @Model (SwiftData):
- startedAt, lastUpdate, pausedAt, accumulatedPausedSeconds, pointsData
- Container in BanYaroGoApp registriert

TrackingView:
- Persistenz alle 5s via Timer
- confirmationDialog beim Erscheinen wenn ActiveWalk vorhanden:
  Fortsetzen / Jetzt speichern / Verwerfen
- Pause/Resume-Button + Stop-Button
- Floating Kamera-Button rechts unten
- Foto-Counter in der Stats-Karte
- Pause-Badge oben links bei Pause

CameraPicker: UIImagePickerController-Wrapper (Fallback auf Library im Simulator).

FinishWalkSheet: initialPhotos: [Data] für Kamera-Fotos während Tour.

RouteDetailView: PhotosPicker zum Hinzufügen von Fotos zu bestehender Tour,
sequentieller Upload mit Progress, Detail wird nach Upload refreshed.

NSCameraUsageDescription in BanYaroGo-Info.plist.

BanYaroGo/Views/RouteDetailView.swift

@@ -1,4 +1,5 @@
 import SwiftUI
+import PhotosUI
 
 struct RouteDetailView: View {
     let routeId: Int
@@ -8,6 +9,11 @@ struct RouteDetailView: View {
     @State private var isLoading = false
     @State private var errorMessage: String?
 
+    @State private var newPhotoSelection: [PhotosPickerItem] = []
+    @State private var isUploadingPhoto = false
+    @State private var photoUploadProgress: (done: Int, total: Int) = (0, 0)
+    @State private var photoErrorMessage: String?
+
     var body: some View {
         ScrollView {
             VStack(alignment: .leading, spacing: 16) {
@@ -30,19 +36,8 @@ struct RouteDetailView: View {
                             .padding(.horizontal)
                     }
 
-                    if let urls = detail.fotoUrls, !urls.isEmpty {
-                        VStack(alignment: .leading, spacing: 8) {
-                            Text("Fotos").font(.headline)
-                            ScrollView(.horizontal, showsIndicators: false) {
-                                HStack(spacing: 10) {
-                                    ForEach(urls, id: \.self) { path in
-                                        photoThumb(path)
-                                    }
-                                }
-                            }
-                        }
+                    photosSection(for: detail)
                         .padding(.horizontal)
-                    }
 
                     Spacer(minLength: 24)
                 } else if isLoading {
@@ -60,6 +55,60 @@ struct RouteDetailView: View {
         .navigationTitle(detail?.name ?? fallbackName)
         .navigationBarTitleDisplayMode(.inline)
         .task { await load() }
+        .onChange(of: newPhotoSelection) { _, items in
+            guard !items.isEmpty else { return }
+            Task { await uploadSelected(items: items) }
+        }
+    }
+
+    @ViewBuilder
+    private func photosSection(for detail: RouteDetail) -> some View {
+        let urls = detail.fotoUrls ?? []
+        VStack(alignment: .leading, spacing: 8) {
+            HStack {
+                Text(urls.isEmpty ? "Fotos" : "Fotos (\(urls.count))")
+                    .font(.headline)
+                Spacer()
+                PhotosPicker(
+                    selection: $newPhotoSelection,
+                    maxSelectionCount: 5,
+                    matching: .images
+                ) {
+                    Label("Foto hinzufügen", systemImage: "photo.badge.plus")
+                        .font(.subheadline)
+                }
+                .disabled(isUploadingPhoto)
+            }
+
+            if isUploadingPhoto {
+                HStack(spacing: 8) {
+                    ProgressView()
+                    Text("Lade \(photoUploadProgress.done + 1)/\(photoUploadProgress.total)…")
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                }
+            }
+
+            if let photoErrorMessage {
+                Text(photoErrorMessage)
+                    .font(.caption)
+                    .foregroundStyle(.red)
+            }
+
+            if !urls.isEmpty {
+                ScrollView(.horizontal, showsIndicators: false) {
+                    HStack(spacing: 10) {
+                        ForEach(urls, id: \.self) { path in
+                            photoThumb(path)
+                        }
+                    }
+                }
+            } else if !isUploadingPhoto {
+                Text("Noch keine Fotos. Über den Button oben kannst du welche hinzufügen.")
+                    .font(.footnote)
+                    .foregroundStyle(.secondary)
+            }
+        }
     }
 
     private func photoThumb(_ path: String) -> some View {
@@ -87,6 +136,34 @@ struct RouteDetailView: View {
         }
     }
 
+    private func uploadSelected(items: [PhotosPickerItem]) async {
+        isUploadingPhoto = true
+        photoErrorMessage = nil
+        photoUploadProgress = (0, items.count)
+        defer {
+            isUploadingPhoto = false
+            newPhotoSelection = []
+        }
+
+        for (index, item) in items.enumerated() {
+            photoUploadProgress = (index, items.count)
+            guard let raw = try? await item.loadTransferable(type: Data.self) else { continue }
+            let resized = ImageResize.resizedJPEG(from: raw)
+            do {
+                try await APIClient.shared.uploadFile(
+                    "/api/routes/\(routeId)/photo",
+                    filename: "photo_\(Int(Date.now.timeIntervalSince1970))_\(index + 1).jpg",
+                    data: resized
+                )
+            } catch {
+                photoErrorMessage = "Foto \(index + 1) konnte nicht hochgeladen werden: \(error.localizedDescription)"
+                break
+            }
+        }
+        // Refresh detail to pick up the new foto_urls.
+        await load()
+    }
+
     private func formatKm(_ km: Double?) -> String {
         guard let km else { return "—" }
         return String(format: "%.2f km", km)